Re: [22.1.90]: Point before start of properties

[Richard Stallman]

The error "point before start of properties" could just as well
be an abort, since it reports a condition that should be impossible.
Namely, that the interval data structure that records the text properties
is invalid, in that it does not cover the whole of the buffer.

The first step in debugging this is to carefully examine the interval
data structure and see how it is invalid.

The next step is to see how it got that way.
Your simple test case should make that fairly easy:

    (gdb) b intervals.c:794
    Breakpoint 1 at 0x195d90: file intervals.c, line 794.
    (gdb) r -Q

    Then in emacs do C-x C-f ~/.../src/intervals.c RET and bang:

    Breakpoint 1, update_interval (i=0x8b1af4, pos=1771) at intervals.c:794
    794                 error ("Point before start of properties");
    (gdb) 

Does anyone else observe this bug?